The invention relates to turbine or compressor blades for a turbine engine, the blades being made of composite material comprising fiber reinforcement densified by a matrix.
The intended domain is that of gas turbines for aeroengines or for industrial turbines.
Proposals have already been made to make turbine engine blades out of composite material, the fiber reinforcement being obtained in particular from carbon or ceramic yarns and the matrix being made out of ceramic material or organic material or carbon.
Document WO 2010/061140 A1 describes a method of fabricating turbine rotor wheel blades out of composite material and incorporating an outer platform or head and an inner platform, by: making a fiber blank by multilayer weaving; shaping the blank by means of tooling in order to obtain a fiber preform having portions forming a preform for a blade airfoil and root, a preform for a blade head, and a preform for a blade inner platform; and then densifying the fiber preform with a matrix. The fiber blank is woven with a first portion in the form of a strip or sheet that is to form the preform for the blade airfoil and root and a second portion in the form of a strip or sheet that is to form the preform for the head and inner platform, the second portion crossing the first portion at the locations of the head and of the inner platform.
Document WO 2011/080443 A1 describes a similar method in which the fiber blank is woven with a first portion in the form of a strip or sheet that is to form a preform for a blade airfoil and root, a second portion in the form of a strip or sheet that is to form a preform for overlapping spoilers of the blade head, and a third portion in the form of a strip or sheet that is to form a preform for wipers of the blade head and a preform for a blade inner platform, the second and third portions crossing the first portion at the locations of the head and of the inner platform. Such a method is relatively complex to implement. In addition, making a woven fiber blank with two crossings leads to large amounts of stress on the yarns, which can lead to yarns breaking, in particular if they are made of carbon or ceramic.
Document US 2012/099982 discloses fabricating a turbine engine stator blade out of composite material with fiber reinforcement densified by a matrix and comprising an airfoil, a first platform situated at one longitudinal end of the airfoil, and at least one functional element extending from the outside face of the first platform.